"It's devastating. It's hard to even wrap your head around. I can't believe he's gone. I think it was just wrong place, wrong time because he was very wise. I would trust him with anything to do with being on the water," said Brenda Wainwright.

She described her brother as "unique ... that rare combination of incredibly intelligent, very kind, great sense of humor."

Police said Saturday the man was scuba diving with two friends near Rottnest Island, a popular tourist destination about 15 miles off the Australian mainland, when the attack occurred.

The man's friends, who were not in the water at the time, noticed an abnormal amount of air bubbles rising to the surface in the area where he was diving, followed by a plume of blood, said police spokesman Michael Wear.

Moments later, the man's body rose to the surface. Police said he succumbed to his injuries not long after the incident. Following a preliminary review of bite marks on the body, authorities said he is believed to have been killed by a great white shark.

"He was in the water by himself, I believe," Sgt. Greg True of Western Australia police told CNN affiliate Channel Nine. "There's been some pretty massive injuries inflicted."

Sharon Wainwright told CNN her family was notified of the incident Saturday morning. Authorities said the man had been living in Western Australia.

Wainright's relatives expect his body to arrive in Florida in about four days, Sharon Wainwright said.

Saturday's attack was the second fatal shark attack in the past two weeks near the city of Perth, capital of the state of Western Australia.

"He was one of a kind," the victim's sister, Brannon, told WMBB.

"He's more than just a quick news spot. He was our brother and we loved him. He will be missed."